Lecture 12 Short Notes Flashcards
What are the primary causes of fractures?
-trauma (direct or indirect)
-pathological factors
-stress protection
-fatigue fractures from repeated stress
-defect in bone due to biopsy or surgery
What is the recommended practice for obtaining radiographs of fractures?
-obtain at least two radiographs at 90 degrees to one another
-include joints above and below the fracture
-examine growth plates in young animals
-radiograph the opposite leg for true bone length assessment
-use horizontal beam if necessary
-increase exposure factors if soft tissue swelling is present
What are the radiographic signs of fractures?
-disruption of normal shape of bone or of the cortex or trabecular pattern
-radiolucent fracture lines
-increased radiopacity of cortex and medulla if folding or impacted fragments occur
-small, free fragments
-ballistics/foreign material/gas
-evidence of fracture healing
-muscle atrophy and disuse osteopenia
What are the classifications of fractures?
-closed or open (compound)
-simple, comminuted, multiple, or segmental
-transverse, oblique, spiral, longitudinal, or irregular
-complete or incomplete
-chip or slab fracture
-articular or non-articular
-avulsion fractures
-fatigue/stress fracture
-impaction/compression fracture
-fracture subluxation
-Salter-Harris fracture
What are Salter-Harris fractures?
fractures involving unfused growth plates that may lead to growth disturbances
What are the stages of secondary fracture healing?
Stage 1: sharp fragments, hairline fractures, soft tissue swelling
Stage 2: blurred fracture margins, reduced swelling
Stage 3: unstructured bony callus, partial bridging
Stage 4: solid callus, early remodeling
Stage 5: continued remodeling, restoration of bone structure
What is primary bone healing?
direct bridging of the fracture by osseous tissue without intermediate callus
What factors can contribute to delayed union of fractures?
-disuse
-instability
-poor reduction
-poor nutrition
-old age
-infection
-poor vascularity
-presence of a sequestrum
-large intramedullary pin
-undetected underlying pathology
What is non-union in fracture healing?
fracture healing has ceased without uniting the fragments, usually after 10-12 weeks
Which fracture occurs from repeated minor trauma?
fatigue or stress fracture
Can radiographs provide information about damage to articular cartilage?
no
What are the complications of fracture healing?
-delayed union
-non-union
-malunion
-excessive callus formation
-osteomyelitis
-sequestrum formation
-fracture disease
-neoplastic transformation
-metallosis
What should be assessed in immediate post-operative radiographs?
-degree of reduction
-alignment (medial-lateral and cranial-caudal)
-adequacy of implant
-joint congruency
-presence of cancellous bone grafts
-soft tissues
What is the purpose of using stressed views in radiography?
to detect fracture (sub)luxations or collateral ligament damage
What is a torus fracture?
A concave side fracture
What does the presence of foreign material in fracture assessment indicate?
Potential complications or infection.
What is the significance of soft tissue changes in fracture assessment?
indicates potential complications or healing issues
What is the typical follow-up interval for radiographs in young animals?
2 to 3 weeks
What can excessive callus formation indicate?
-movement at fracture site
-infection
-periosteal stripping
-incorporation of bone grafts
What are the characteristics of hypertrophic non-union?
new bone surrounds ends but does not cross the fracture line, appearing bell-shaped
Which types of fractures are most common in young animals?
Salter-Harris fractures
What is a sequestrum formation?
devitalized piece of bone that will impede healing and/or lead to sinus formation
What is fracture disease?
a clinical syndrome with joint stiffness and muscle wastage due to disease; radiographs show osteopenia
What are the characteristics of neoplastic transformation in the context of bone fractures?
-may occur years later, especially if metallic implants are present or healing was complex
-possibly due to chronic inflammation
-usually seen in fractures that occur between 1 and 3 years of age
What is metallosis?
a sterile, chronic, proliferative osteomyelitis resulting from a reaction to metallic implants, especially when dissimilar metals are used
How can ultrasonography be used in the assessment of fracture healing?
it can assess soft tissues and bony surfaces of fractures and calluses, detecting healing earlier than radiography
What does Stage 1 of fracture healing look like ultrasonographically?
homogeneous, hypoechoic soft tissue in the gap between the fragment ends
What does Stage 2 of fracture healing look like ultrasonographically?
heterogeneous, hypoechoic soft tissue in the fracture gap, occurring 1–2 weeks after injury
What does Stage 3 of fracture healing look like ultrasonographically?
heterogeneous, irregular appearance with hyperechoic areas indicating the start of mineralization, occurring 2–3 weeks post-injury
What does Stage 4 of fracture healing look like ultrasonogroaphically?
heterogeneous callus becoming continuous and lamellar, occurring 3–8 weeks after injury
What does Stage 5 of fracture healing look like ultrasonographically?
continuous, smooth, hyperechoic line representing the healed cortex, with intramedullary implants no longer identifiable, occurring 8 weeks onward
What can cause bowing of the bones?
-“normal” change in chondrodystrophic breed
-growth plate trauma/uneven growth
-bowstring effect
-chondrodysplasia
-rickets
-congenital hypothyroidism
-asymmetric bridging of a growth plate
-tension from shortened soft tissues
-altered stresses due to bone or joint disease
-hemimelia/absence of radius or ulna
What are possible causes of pathological fractures?
-primary hyperparathyroidism
-secondary hyperparathyroidism
-pseudohyperparathyroidism
-neoplasia
-enchondromatosis
-bone cyst
-osteomyelitis
What can cause angulation of bone?
-traumatic folding/greenstick fracture
-pathological fracture
What is secondary bone healing?
unstructured bone laid down in soft tissue as a callus and subsequently remodeled
What are the steps to fracture assessment at time of injury?
-location
-age of fracture
-type of fracture
-displacement of fragments
-underlying bone radiolucency
-involvement of joints
-presence of foreign material
-soft tissue changes
-injuries elsewhere in body
